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Randomized trials published in higher vs. lower impact journals differ in design, conduct, and analysis
Malgorzata M Bala1, Elie A Akl, Xin Sun
12nd Department of Internal Medicine, Jagiellonian University School of Medicine, Skawinska 8, 31-066 Krakow, Poland.
Journal of Clinical Epidemiology
|January 26, 2013
Summary
Randomized controlled trials (RCTs) in high-impact journals showed better methods and outcomes than those in lower-impact journals. However, publication in a top journal does not guarantee low risk of bias.
Area of Science:
- Clinical Research Methodology
- Medical Journal Impact Factors
- Evidence-Based Medicine
Background:
- Assessing the methodological quality of randomized controlled trials (RCTs) is crucial for reliable medical evidence.
- Journal impact factor is often used as a proxy for research quality, but its relationship with RCT methodology needs examination.
Purpose of the Study:
- To compare the methodological characteristics of RCTs published in high-impact versus lower-impact Core Clinical Journals.
- To determine if journal impact influences the reporting of bias-reducing strategies and patient-important outcomes in RCTs.
Main Methods:
- A systematic search of MEDLINE identified RCTs published in 2007 in Core Clinical Journals.
- A 1:1 random sampling of 1,140 study reports was conducted, comparing high-impact (top 5 general medicine journals by citation) with lower-impact journals.
Main Results:
- Eligible RCTs (n=469) included 219 from high-impact and 250 from lower-impact journals.
- RCTs in higher impact journals had larger sample sizes, more industry funding, and better reporting of allocation concealment, blinding, patient-important outcomes, and subgroup analyses (all P < 0.05).
Conclusions:
- RCTs in higher impact journals demonstrate superior methodological safeguards against bias and reporting of patient-important outcomes.
- Despite improvements, publication in high-impact journals does not definitively ensure a low risk of bias in RCTs.
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